static
VOID
InsertTimedQueue(
PRING pTimed,
PLW_TASK pInsert
)
{
PLW_TASK pTask = NULL;
PRING pRing = NULL;
/* Find the first task in the queue with a later deadline than the task to insert */
for (pRing = pTimed->pNext; pRing != pTimed; pRing = pRing->pNext)
{
pTask = LW_STRUCT_FROM_FIELD(pRing, EPOLL_TASK, QueueRing);
if (pTask->llDeadline > pInsert->llDeadline)
break;
}
/* Insert the task */
RingInsertBefore(pRing, &pInsert->QueueRing);
}
NTSTATUS
LwRtlCreateTask(
PLW_THREAD_POOL pPool,
PLW_TASK* ppTask,
PLW_TASK_GROUP pGroup,
LW_TASK_FUNCTION pfnFunc,
PVOID pContext
)
{
NTSTATUS status = STATUS_SUCCESS;
PEPOLL_TASK pTask = NULL;
PEPOLL_THREAD pThread = NULL;
ULONG ulMinLoad = 0xFFFFFFFF;
ULONG ulIndex = 0;
if (pPool->pDelegate)
{
return LwRtlCreateTask(pPool->pDelegate, ppTask, pGroup, pfnFunc, pContext);
}
status = LW_RTL_ALLOCATE_AUTO(&pTask);
GOTO_ERROR_ON_STATUS(status);
RingInit(&pTask->GroupRing);
RingInit(&pTask->QueueRing);
RingInit(&pTask->SignalRing);
pTask->pGroup = pGroup;
pTask->ulRefCount = 2;
pTask->pfnFunc = pfnFunc;
pTask->pFuncContext = pContext;
pTask->Fd = -1;
pTask->EventArgs = LW_TASK_EVENT_INIT;
pTask->EventWait = LW_TASK_EVENT_EXPLICIT;
pTask->llDeadline = 0;
LOCK_POOL(pPool);
for (ulIndex = 0; ulIndex < pPool->ulEventThreadCount; ulIndex++)
{
if (pPool->pEventThreads[ulIndex].ulLoad < ulMinLoad)
{
pThread = &pPool->pEventThreads[ulIndex];
ulMinLoad = pThread->ulLoad;
}
}
pTask->pThread = pThread;
if (pGroup)
{
LOCK_GROUP(pGroup);
if (pGroup->bCancelled)
{
UNLOCK_GROUP(pGroup);
UNLOCK_POOL(pPool);
status = STATUS_CANCELLED;
GOTO_ERROR_ON_STATUS(status);
}
RingInsertBefore(&pGroup->Tasks, &pTask->GroupRing);
UNLOCK_GROUP(pGroup);
}
pThread->ulLoad++;
UNLOCK_POOL(pPool);
*ppTask = pTask;
cleanup:
return status;
error:
if (pTask)
{
TaskDelete(pTask);
}
*ppTask = NULL;
goto cleanup;
}
NTSTATUS
LwRtlCreateTask(
PLW_THREAD_POOL pPool,
PLW_TASK* ppTask,
PLW_TASK_GROUP pGroup,
LW_TASK_FUNCTION pfnFunc,
PVOID pContext
)
{
NTSTATUS status = STATUS_SUCCESS;
PSELECT_TASK pTask = NULL;
if (pPool->pDelegate)
{
return LwRtlCreateTask(pPool->pDelegate, ppTask, pGroup, pfnFunc, pContext);
}
GOTO_ERROR_ON_STATUS(status = LW_RTL_ALLOCATE_AUTO(&pTask));
RingInit(&pTask->GroupRing);
RingInit(&pTask->EventRing);
pTask->pPool = pPool;
pTask->pGroup = pGroup;
pTask->ulRefCount = 2;
pTask->pfnFunc = pfnFunc;
pTask->pFuncContext = pContext;
pTask->Fd = -1;
pTask->TriggerSet = LW_TASK_EVENT_INIT;
pTask->TriggerWait = LW_TASK_EVENT_EXPLICIT;
pTask->llDeadline = 0;
LOCK_POOL(pPool);
if (pGroup)
{
LOCK_GROUP(pGroup);
if (pGroup->bCancelled)
{
UNLOCK_GROUP(pGroup);
UNLOCK_POOL(pPool);
status = STATUS_CANCELLED;
GOTO_ERROR_ON_STATUS(status);
}
RingInsertBefore(&pGroup->Tasks, &pTask->GroupRing);
}
pTask->pThread = &pPool->pEventThreads[pPool->ulNextEventThread];
pPool->ulNextEventThread = (pPool->ulNextEventThread + 1) % pPool->ulEventThreadCount;
UNLOCK_POOL(pPool);
LOCK_THREAD(pTask->pThread);
RingInsertBefore(&pTask->pThread->Tasks, &pTask->EventRing);
/* It's not necessary to signal the thread about the new task here
since it won't be run anyway */
UNLOCK_THREAD(pTask->pThread);
if (pGroup)
{
UNLOCK_GROUP(pGroup);
}
*ppTask = pTask;
error:
return status;
}
static
NTSTATUS
EventLoop(
PSELECT_THREAD pThread
)
{
NTSTATUS status = STATUS_SUCCESS;
RING tasks;
RING runnable;
PRING pRing = NULL;
PRING pNext = NULL;
PSELECT_TASK pTask = NULL;
CLOCK clock = {0};
LONG64 llNow;
LONG64 llNextDeadline;
fd_set readSet;
fd_set writeSet;
fd_set exceptSet;
int ready = 0;
int nfds = 0;
char c = 0;
int res = 0;
BOOLEAN bShutdown = FALSE;
PLW_TASK_GROUP pGroup = NULL;
BOOLEAN bYielding = FALSE;
RingInit(&tasks);
RingInit(&runnable);
FD_ZERO(&readSet);
FD_ZERO(&writeSet);
FD_ZERO(&exceptSet);
LOCK_THREAD(pThread);
while (!bShutdown || !RingIsEmpty(&tasks))
{
/* Reset variables */
llNextDeadline = 0;
nfds = 0;
bYielding = FALSE;
/* Get current time for this iteration */
GOTO_ERROR_ON_STATUS(status = ClockGetMonotonicTime(&clock, &llNow));
/* Figure out which tasks are runnable */
for (pRing = tasks.pNext; pRing != &tasks; pRing = pNext)
{
pNext = pRing->pNext;
pTask = LW_STRUCT_FROM_FIELD(pRing, SELECT_TASK, EventRing);
/* Update trigger set with results from select() */
UpdateTriggerSet(
pTask,
&readSet,
&writeSet,
&exceptSet,
llNow);
/* Schedule tasks to run if they have been triggered or were yielding */
if ((pTask->TriggerWait & LW_TASK_EVENT_YIELD) ||
((pTask->TriggerWait | LW_TASK_EVENT_EXPLICIT) & pTask->TriggerSet))
{
/* Put task on a separate list to run its trigger function */
RingRemove(&pTask->EventRing);
RingInsertBefore(&runnable, &pTask->EventRing);
/* Update the trigger args with the trigger set */
pTask->TriggerArgs |= pTask->TriggerSet;
/* Turn off bits (except cancel) now that we have copied them */
pTask->TriggerSet &= (LW_TASK_EVENT_CANCEL);
}
else
{
/* Update select parameters to wait for task to trigger */
UpdateTriggerWait(
pTask,
&nfds,
&readSet,
&writeSet,
&exceptSet,
&llNextDeadline);
}
}
UNLOCK_THREAD(pThread);
for (pRing = runnable.pNext; pRing != &runnable; pRing = pNext)
{
pNext = pRing->pNext;
pTask = LW_STRUCT_FROM_FIELD(pRing, SELECT_TASK, EventRing);
GOTO_ERROR_ON_STATUS(status = TaskProcessTrigger(pTask, llNow));
if (pTask->TriggerWait != 0)
{
/* Task is still waiting to be runnable, update select parameters
and put it back in the task list */
UpdateTriggerWait(
pTask,
&nfds,
&readSet,
&writeSet,
&exceptSet,
&llNextDeadline);
if (pTask->TriggerWait & LW_TASK_EVENT_YIELD)
{
/* Task is yielding temporarily. Set the yield flag on
its trigger arguments. Leave it on the runnable list */
pTask->TriggerArgs |= LW_TASK_EVENT_YIELD;
}
else
{
RingRemove(&pTask->EventRing);
RingInsertBefore(&tasks, &pTask->EventRing);
}
}
else
{
/* Task is complete, notify and remove from task group
if it is in one */
RingRemove(&pTask->EventRing);
/* Unregister task from global signal loop */
if (pTask->pUnixSignal)
{
RegisterTaskUnixSignal(pTask, 0, FALSE);
}
pGroup = pTask->pGroup;
if (pGroup)
{
LOCK_GROUP(pGroup);
pTask->pGroup = NULL;
RingRemove(&pTask->GroupRing);
pthread_cond_broadcast(&pGroup->Event);
UNLOCK_GROUP(pGroup);
}
LOCK_THREAD(pThread);
if (--pTask->ulRefCount)
{
pTask->TriggerSet = TASK_COMPLETE_MASK;
pthread_cond_broadcast(&pThread->Event);
UNLOCK_THREAD(pThread);
}
else
{
UNLOCK_THREAD(pThread);
TaskDelete(pTask);
}
}
}
if (!RingIsEmpty(&runnable))
{
/* We have runnable tasks that are yielding. Move them
back to the event list and note the fact. */
bYielding = TRUE;
RingMove(&runnable, &tasks);
}
if (!bShutdown)
{
/* Also wait for a poke on the thread's signal fd */
FD_SET(pThread->SignalFds[0], &readSet);
if (pThread->SignalFds[0] >= nfds)
{
nfds = pThread->SignalFds[0] + 1;
}
}
if (nfds)
{
/* If there are still runnable tasks due to
LW_TASK_EVENT_YIELD, set the next deadline
to now so we wake immediately. This gives other
tasks the chance to become runnable before we
proceed */
if (bYielding)
{
llNextDeadline = llNow;
}
/* Wait for a task to be runnable */
GOTO_ERROR_ON_STATUS(status = Sleep(
&clock,
&llNow,
nfds,
&readSet,
&writeSet,
&exceptSet,
llNextDeadline,
&ready));
}
LOCK_THREAD(pThread);
/* Check for a signal to the thread */
if (FD_ISSET(pThread->SignalFds[0], &readSet))
{
FD_CLR(pThread->SignalFds[0], &readSet);
pThread->bSignalled = FALSE;
res = read(pThread->SignalFds[0], &c, sizeof(c));
assert(res == sizeof(c));
/* Move all tasks in queue into local task list */
RingMove(&pThread->Tasks, &tasks);
if (pThread->bShutdown && !bShutdown)
{
bShutdown = pThread->bShutdown;
/* Cancel all outstanding tasks */
for (pRing = tasks.pNext; pRing != &tasks; pRing = pRing->pNext)
{
pTask = LW_STRUCT_FROM_FIELD(pRing, SELECT_TASK, EventRing);
pTask->TriggerSet |= LW_TASK_EVENT_CANCEL | LW_TASK_EVENT_EXPLICIT;
}
}
}
}
error:
UNLOCK_THREAD(pThread);
return status;
}
